What can the walls of an ancient pot teach us about meals in the Indus cities?

Animal fats, and dairy only here and there. Residues in vessels from Indus sites in northwest India carried mainly signs of fats from animals, including fat from animals that are not ruminants. Signals identified as dairy appeared in only a limited share of the samples. A find like that paints a more varied diet than anyone could guess from the animal bones alone.

Bones at an archaeological site show which animals were present, and not necessarily how they were used for cooking. Fat absorbed into the wall of a vessel adds a different kind of evidence.

The team extracted fat residues from pottery at several sites and compared the chemical compositions with known fat signatures. They found widespread use of animal products, with a notable share of fats that do not come from ruminants.

Signs of dairy processing appeared only in a limited way in this assemblage. That does not overturn other evidence for dairy consumption in the Indus Civilization; it shows the pattern varied between vessels and sites.

A pot may serve many dishes, and the preservation of fat depends on temperature, on soil and on elapsed time. So the find reads as a partial window onto food habits, not as a daily menu for every inhabitant.